The genetic basis of color-related local adaptation in a ring-like colonization around the Mediterranean.

Uncovering the genetic basis of phenotypic variation and the population history under which it established is key to understand the trajectories along which local adaptation evolves. Here, we investigated the genetic basis and evolutionary history of a clinal plumage color polymorphism in European barn owls (Tyto alba). Our results suggest that barn owls colonized the Western Palearctic in a ring-like manner around the Mediterranean and meet in secondary contact in Greece. Rufous coloration appears to be linked to a recently evolved nonsynonymous-derived variant of the melanocortin 1 receptor (MC1R) gene, which according to quantitative genetic analyses evolved under local adaptation during or following the colonization of Central Europe. Admixture patterns and linkage disequilibrium between the neutral genetic background and color found exclusively within the secondary contact zone suggest limited introgression at secondary contact. These results from a system reminiscent of ring species provide a striking example of how local adaptation can evolve from derived genetic variation

Molecular evolution of the proopiomelanocortin system in Barn owl species.

Examination of genetic polymorphisms in outbred wild-living species provides insights into the evolution of complex systems. In higher vertebrates, the proopiomelanocortin (POMC) precursor gives rise to α-, β-, and γ-melanocyte-stimulating hormones (MSH), which are involved in numerous physiological aspects. Genetic defects in POMC are linked to metabolic disorders in humans and animals. In the present study, we undertook an evolutionary genetic approach complemented with biochemistry to investigate the functional consequences of genetic polymorphisms in the POMC system of free-living outbred barn owl species (family Tytonidae) at the molecular level. Our phylogenetic studies revealed a striking correlation between a loss-of-function H9P mutation in the β-MSH receptor-binding motif and an extension of a poly-serine stretch in γ3-MSH to ≥7 residues that arose in the barn owl group 6-8 MYA ago. We found that extension of the poly-serine stretches in the γ-MSH locus affects POMC precursor processing, increasing γ3-MSH production at the expense of γ2-MSH and resulting in an overall reduction of γ-MSH signaling, which may be part of a negative feedback mechanism. Extension of the γ3-MSH poly-serine stretches ≥7 further markedly increases peptide hormone stability in plasma, which is conserved in humans, and is likely relevant to its endocrine function. In sum, our phylogenetic analysis of POMC in wild living owls uncovered a H9P β-MSH mutation subsequent to serine extension in γ3-MSH to 7 residues, which was then followed by further serine extension. The linked MSH mutations highlight the genetic plasticity enabled by the modular design of the POMC gene

A Global Network of Science and Technology Advice in Foreign Ministries

This paper is a product of the International Dialogue on Science and Technology Advice in Foreign Ministries (Vienna Dialogue) in October 2016, involving more than twenty nations and several international organisations. The event was a key step to further develop the Foreign Minister Science and Technology Advisor Network (FMSTAN), growing from an initial group of five nations. The Vienna Dialogue was convened by the Fletcher School of Law and Diplomacy, Tufts University, and the International Institute for Applied Systems Analysis (IIASA) at the Vienna headquarters of IIASA, bringing together diplomats from foreign ministries to consider the value of evidence for informed decision-making by nations with regard to issues, impacts and resources within, across and beyond national boundaries. The evidence comes from the natural and social sciences with engineering and medicine as well as other areas of technology. By building common interests among nations, science is a tool of diplomacy, promoting cooperation and preventing conflict in our world. Science diplomacy was discussed as an international, interdisciplinary and inclusive process to help balance national interests and common interests in view of urgencies today and across generations in our globally-interconnected civilization

Eda haplotypes in three-spined stickleback are associated with variation in immune gene expression

Haplotypes underlying local adaptation and speciation are predicted to have numerous phenotypic effects, but few genes involved have been identified, with much work to date concentrating on visible, morphological, phenotypes. The link between genes controlling these adaptive morphological phenotypes and the immune system has seldom been investigated, even though changes in the immune system could have profound adaptive consequences. The Eda gene in three-spined stickleback is one of the best studied major adaptation genes; it directly controls bony plate architecture and has been associated with additional aspects of adaptation to freshwater. Here, we exposed F2 hybrids, used to separate Eda genotype from genetic background, to contrasting conditions in semi-natural enclosures. We demonstrate an association between the Eda haplotype block and the expression pattern of key immune system genes. Furthermore, low plated fish grew less and experienced higher burdens of a common ectoparasite with fitness consequences. Little is currently known about the role of the immune system in facilitating adaptation to novel environments, but this study provides an indication of its potential importance

Differential response of human basophil activation markers: a multi-parameter flow cytometry approach

<p>Abstract</p> <p>Background</p> <p>Basophils are circulating cells involved in hypersensitivity reactions and allergy but many aspects of their activation, including the sensitivity to external triggering factors and the molecular aspects of cell responses, are still to be focused. In this context, polychromatic flow cytometry (PFC) is a proper tool to investigate basophil function, as it allows to distinguish the expression of several membrane markers upon activation in multiple experimental conditions. </p> <p>Methods</p> <p>Cell suspensions were prepared from leukocyte buffy coat of K2-EDTA anticoagulated blood specimens; about 1500-2500 cellular events for each tested sample, gated in the lymphocyte CD45dim area and then electronically purified as HLADRnon expressing/CD123bright, were identified as basophilic cells. Basophil activation with fMLP, anti-IgE and calcium ionophore A23187 was evaluated by studying up-regulation of the indicated membrane markers with a two-laser six-color PFC protocol.</p> <p>Results</p> <p>Following stimulation, CD63, CD13, CD45 and the ectoenzyme CD203c up-regulated their membrane expression, while CD69 did not; CD63 expression occurred immediately (within 60 sec) but only in a minority of basophils, even at optimal agonist doses (in 33% and 14% of basophils, following fMLP and anti-IgE stimulation respectively). CD203c up-regulation occurred in the whole basophil population, even in CD63non expressing cells. Dose-dependence curves revealed CD203c as a more sensitive marker than CD63, in response to fMLP but not in response to anti-IgE and to calcium ionophore.</p> <p>Conclusion</p> <p>Use of polychromatic flow cytometry allowed efficient basophil electronic purification and identification of different behaviors of the major activation markers. The simultaneous use of two markers of activation and careful choice of activator are essential steps for reliable assessment of human basophil functions.</p

The MC1R gene in the guppy (Poecilia reticulata): Genotypic and phenotypic polymorphisms

<p>Abstract</p> <p>Background</p> <p>The guppy (<it>Poecilia reticulata</it>) is an important model organism for studying sexual selection; male guppies have complex and conspicuous pigmentation, and female guppies exhibit preferences for males with specific color spots. Understanding the genetic basis underlying pigmentation variation in the guppy is important for exploring the factors causing the maintenance of color polymorphism in wild populations.</p> <p>Findings</p> <p>We focused on the melanic black pigmentation of guppies, and examined genetic variations in the <it>melanocortin 1 receptor </it>(<it>MC1R</it>) gene because variation in this gene is known to contribute to polymorphism of melanin pigmentation in several animal species. The complete coding sequence of the guppy <it>MC1R </it>gene was determined, and two different <it>MC1R </it>alleles (963 and 969 bp) were found in wild populations. Ornamental strain guppies with a 963-bp <it>MC1R </it>tended to show less black pigmentation than those with a 969-bp <it>MC1R</it>, although the association between <it>MC1R </it>genotype and black pigmentation disappeared in the F₂offspring.</p> <p>Conclusions</p> <p>The guppy <it>MC1R </it>gene showed variation in the five wild Trinidadian populations we examined, and these populations also differed in terms of allele frequencies. We identified a significant association between black pigmentation and <it>MC1R </it>genotype in fish obtained from aquarium shops. However, the results from F₂families suggest that there are other genes that modify the effects of the <it>MC1R </it>gene.</p

Age-dependent relationships between multiple sexual pigments and condition in males and females

The reliability of sexual signaling may change across age classes due to shifts in resource allocation patterns. Two contrasting hypotheses exist regarding how the condition dependence of ornaments may shift with age, and both have received empirical support. On one hand, ornaments may more reliably reflect condition and quality in older individuals, because younger individuals of high quality invest in survival over signaling effort. On the other hand, the condition dependence of ornaments may decline with age, if older individuals in poor condition terminally invest in ornaments, or if resource constraints decline with age. Further, the expression and condition dependence of different ornaments may shift with age in unique ways, such that multifaceted sexual displays maintain reliable signaling across age classes. In yellow warblers (Setophaga petechia) of both sexes, we assessed how relationships between carotenoid-and phaeomelanin-based sexual pigmentation, prenesting body reserves, and condition at molt (reflected by growth bars and feather quality) vary across age classes. Melanin coverage correlated with condition at molt across age classes in males and showed high repeatability in both sexes. In contrast, carotenoid saturation increased longitudinally with age in males and correlated with condition at molt in different age classes in the 2 sexes. Specifically, carotenoid saturation correlated positively with condition at molt in younger, but not older males, whereas in females, the situation was reversed, with a positive correlation present only in older females. Results suggest that age-dependent signaling may promote maintenance of multifaceted sexual displays and that agedependent signaling dynamics depend on sex. © The Author 2013. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved

Haste Makes Waste: Accelerated Molt Adversely Affects the Expression of Melanin-Based and Depigmented Plumage Ornaments in House Sparrows

. Costly life-history events are adaptively separated in time, thus, when reproduction is extended, the time available for molt is curtailed and, in turn, molt rate is accelerated.We experimentally accelerated the molt rate by shortening the photoperiod in order to test whether this environmental constraint is mirrored in the expression of plumage ornaments. Sparrows which had undergone an accelerated molt developed smaller badges and less bright wing-bars compared to conspecifics that molted at a natural rate being held at natural-like photoperiod. There was no difference in the brightness of the badge or the size of the wing-bar.These results indicate that the time available for molt and thus the rate at which molt occurs may constrain the expression of melanin-based and depigmented plumage advertisements. This mechanism may lead to the evolution of honest signaling if the onset of molt is condition-dependent through the timing of and/or trade-off between breeding and molt